mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-03 12:05:13 +02:00
c2bbdee765
commit0a663b764dupstream. When multiple syscall events are specified in the kernel command line (e.g., trace_event=syscalls:sys_enter_openat,syscalls:sys_enter_close), they are often not captured after boot, even though they appear enabled in the tracing/set_event file. The issue stems from how syscall events are initialized. Syscall tracepoints require the global reference count (sys_tracepoint_refcount) to transition from 0 to 1 to trigger the registration of the syscall work (TIF_SYSCALL_TRACEPOINT) for tasks, including the init process (pid 1). The current implementation of early_enable_events() with disable_first=true used an interleaved sequence of "Disable A -> Enable A -> Disable B -> Enable B". If multiple syscalls are enabled, the refcount never drops to zero, preventing the 0->1 transition that triggers actual registration. Fix this by splitting early_enable_events() into two distinct phases: 1. Disable all events specified in the buffer. 2. Enable all events specified in the buffer. This ensures the refcount hits zero before re-enabling, allowing syscall events to be properly activated during early boot. The code is also refactored to use a helper function to avoid logic duplication between the disable and enable phases. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260224023544.1250787-1-hehuiwen@kylinos.cn Fixes:ce1039bd3a("tracing: Fix enabling of syscall events on the command line") Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>